When I run tests I get the error "Command line is too long". It works if I set the "Shorten command line" method in the Run/Debug configuration to "JAR manifest" for the specific method or class, but how do I set it for the whole project or is there an IDE global setting for it?
You can set up a default way to shorten the command line and use it as a template for further configurations by changing the default JUnit Run/Debug Configuration template. Then all new Run/Debug configuration you create in project will use the same option.
Here is the related blog post about configurable command line shortener option.